In the North, Lincoln told Major General Joseph Hooker to have the Union army follow Lee's army.[9] But Hooker was very reluctant to go after the Confederates. Finally, Lincoln lost all confidence in him.[9] On June 28, three days before the Battle of Gettysburg, Lincoln appointed General Meade to replace Hooker.[9] Had the Confederacy won, confederate force would have had access to Philadelphia or Baltimore.[15] Vice President Alexander Hamilton went to Lincoln to discuss a prisoner of war trade five days before the Battle of Gettysburg.[16]

Neither Lee nor Meade intended a battle take place at Gettysburg and neither were there when the battle started.[17] On June 30, 1863, Confederate General Henry Heth had a division at Cashtown, Pennsylvania, Lee's gathering place before moving on to Harrisburg. Heth sent his division to nearby Gettysburg to look for, as he later wrote in his report, "army supplies (shoes especially), and return the same day."[18] This started the myth that the Battle of Gettysburg started over shoes.[c][18] Heth did this without scouting ahead to see what was at Gettysburg. The job of scouting belonged to the Confederate cavalry under J.E.B. Stuart.[18] But they had been gone for over a week.[18] So, blind to what was ahead of them, his soldiers ran directly into a Union cavalry division commanded by General John Buford.[17] This started the fighting even though Heth and other commanders were under orders from Lee not to start a battle.[18] But, as each side brought in more troops, it became a full-scale battle.[17] Lee started moving much of his army there. One of his goals was to fight the Union army and destroy it. Now, he would have to do it at Gettysburg.

About 5.30 a.m. on the morning of July 1, the battle started. Heth probed ahead cautiously to a point about two miles west of Gettysburg.[21] Buford's cavalry was deliberately slowing his progress. At about 10 a.m. the Union I Corps arrived commanded by General John F. Reynolds.[21] They set themselves up along McPherson's Ridge to oppose Heth's Confederates. During the fighting Reynolds were killed but the Confederates were driven back. Meanwhile both sides brought up reinforcements.[21] The Union set up defenses of the town with I Corps defending the western approaches with XI Corps to the north. The flanks were covered by Buford's cavalry. One Union division was held in reserve on Cemetery Ridge. In the afternoon, when Lee arrived, the Confederates still did not know the strength of the Union forces they were facing.[21] They also had not scouted the terrain.[21] One division of Ewell's Corps had attacked the Union I Corps just after noon.[21] At about 2 p.m. Heth's division joined Ewell's troops in the attack on I Corps.[21] At about 3 p.m., another of Ewell's Confederate divisions, commanded by General Jubal Early, attacked the flank of the Union XI Corps.[21] By 4 p.m., both of the Union corps retreated through Gettysburg and took up positions on Cemetery Ridge.[21] So far, the Union had lost about 9,000 men including about 3,000 who had been captured.[21] The Confederates had lost about 6,500 men by this point.[21] So the first day of battle was technically a Confederate victory numbers-wise. But Federal troops held the high ground as more reinforcements were still arriving.[21] Based on the first day's fighting, Lee was convinced he could defeat Meade at Gettysburg.[21]

Late in the day, Lee sent the famous order to Confederate General Richard S. Ewell to take cemetery ridge “if practicable.”[d][10] While he had been awaiting orders from Lee, Ewell had ridden out to take a closer look at Cemetery Ridge.[24] Based on what he saw and the confusing order, he decided it was not practicable to take the hill and set up camp.[23] Instead, he decided to leave the assault for the next day. This was the first major mistake of the battle for South. The Army of the Potomac would end the day with around 21,900 men strongly positioned on Culp’s Hill and Cemetery Ridge. The Army of Northern Virginia would have around 27,000 men from Benner’s Hill to Seminary Ridge.

On the second day of battle, most of both armies had arrived. The Union line held the high ground in a defensive formation that looked like a fishhook. On July 2, Lee ordered General James Longstreet, commander of the Confederate I Corps, to attack the Union left flank as early in the day as possible.[25] At the same time General A. P. Hill’s corps was to attack the Union center.[25] General Ewell was to make diversionary attacks and "if practicable" attack the Union Army's right flank.[25] Lee felt that if everything went according to his plan and the Union line was destroyed, the battle, and possibly the war, would be won on the second day.[25] Lee's coordinated attack required getting all the infantry into position and moving up artillery to support them.[26] Longstreet had the furthest to go and midway in their march realized the Union lines could see them. They went back and had to take a different route.[26] Longstreet could not get his corps into position until about 4 p.m. when he began his attack.[26] His attack on the Union line lasted for over three hours but could not break the Union line.[26] Hill's Corps failed to be effective in the center.[26] Ewell did not attack Cemetery Ridge as instructed in Lee's confusing order, but made some progress in taking Culp's Hill.[26]

Union Major General Daniel Sickles, a political general commanding III Corps, disobeyed Meade's orders and moved his troops forward to the Peach Orchard.[27] He had been ordered to take up a position on Little Round Top connecting with Union forces on both his right and left. By doing this he left a large hole in the Union line. He marched to a position nearly 1 mile (1.6 km) in front of the Union line with no support on either side.[28] Within an hour, his entire III Corps was nearly wiped out by Longstreet.[28] Sickles was badly wounded by a cannonball and lost a leg. Being wounded was all that saved him from a court-martial.[28] Sickles' blunder nearly lost the entire battle for the Union.[29]

On the night of July 2, Longstreet’s largest division commanded by General George Pickett arrived and was placed in the center of the Confederate line. Lee’s plan for the next day was to attack on both the Union right and left, just as he had done the day before.[30] Lee was still certain he could break the Union line and win the battle.[30] That day Stuart's cavalry had caught up with Lee's army and Lee ordered Stuart to ride around the East side of Gettysburg and attack the Union rear.[30] Ewell had also been reinforced and was ordered to take Culp's Hill the next morning.[30]

Meade ordered the Union XII Corps to drive Ewell's forces off the captured trenches on Culp's Hill.[30] They were to move at daylight the next morning.[30] He was determined the remainder of the Union Army would hold its position and wait for Lee to attack.[30]

First, a bombardment by about 140 Confederate cannons on the Union lines was ordered.[30] The bombardment started about 1 p.m.[32] About 80 Union cannons returned fire.[33] The cannons duel lasted for between one and two hours, depending on the source (most say about an hour).[32] The Confederate artillery chief, General Edward Porter Alexander, had only intended it to last for about 25 minutes.[32] But he then realized it had done little damage to the Union line so he continued.[32] But he also had to worry about running out of ammunition and not have enough to support the charge that was Pickett was about to make.[32] When the Union guns fell silent, Porter thought he had knocked them out.[32] But it was a trick by the Union artillery chief.[32] His guns were waiting for the charge the Union forces knew was coming. Alexander sent word to Pickett he could start his attack.

The cannonade could be heard as far away as Philadelphia.[34] The noise was so loud the gunner's ears bled.[35] It was probably the loudest noise that had ever been heard on the North American continent up to that time.[34] In the end the Confederate cannons may have killed as many as 200 Union soldiers in the area that would later become known as the "bloody angle".[32] But the Union guns may have killed more Confederate troops.[32]

Calling the Confederate attack on the Union center "Pickett's Charge" is misleading for two reasons.[36] First, Pickett commanded only one of the three units in the assault.[36] Second, it was not a charge, which is a rapid advance towards the enemy, it was an attack which moved forward more slowly and over a longer distance.[36] These Virginia units were joined by several smaller units of Confederates (some from North Carolina, Tennessee and Alabama) whose numbers had been reduced by the fighting over the first two days.[31] When the cannons stopped, Pickett went to Longstreet to ask permission to begin the attack.[35] Longstreet, sure the attack would fail, silently nodded his head and gave a wave of his hand.[35] Longstreet had tried to get Lee to call off the attack, but Lee would not listen.[35]

Over 12,000 Confederates stepped out from the trees and formed up for the long march forward.[35] Waiting for them behind a low stonefence on Cemetery Ridge were about 5,000 Union troops, most of whom belonged to General Winfield Scott Hancock's II Corps.[31] Depending on the source, this was between 2:00 and 3:00 p.m.[31] As they marched forward across the 1 mile (1.6 km) distance, Union artillery killed large numbers of troops.[37] Rifle fire from the Union line was intense. The Union troops used four lines of soldiers.[36] As the line in front fired, they moved back to reload while the next line moved up to fire.[36] Only a few hundred of the Virginians reached the Union line. Within minutes they were dead or dying.[37] Some were captured. The attack lasted about an hour with over 7,000 Confederate soldiers killed.[37] As the remaining Confederate troops retreated, Lee was seen riding his horse saying "this was all my fault".[38] He then told Pickett to rally his division. Pickett famously replied, "General, I have no division."[38]

At about the same time as the main attack, Stuart’s cavalry attacked the Union rear but the attack also failed.[39]

Lee brought an army into Pennsylvania that numbered 75,054 men and lost 22,638 casualties or about 30% of his army.[40] Meade lost so many field grade officers that the Army of the Potomac would not recover for the rest of the war.[40] Both the Union I Corps and III Corps lost so many men they had to be combined with II Corps.[40] The battle took more American lives than any other battle in United States history. Gettysburg is still the largest battle to ever be fought on American soil. The Union victory over the Confederacy ended Lee’s invasion of the north. Lee would never try to invade the Union again. The Army of Northern Virginia would never get their strength back. However the supplies taken during their time in Pennsylvania would keep the Confederate army going.[41] The wagon train of supply wagons and ambulances for the wounded was over 17 miles (27 km) long.[41] Lee never had more than 51,000 men the rest of the war. Numbers from the Union forces wore down Lee and his army. This is why Gettysburg is said to be the turning point of the American Civil War. After the battle the confederates figured out that there was a slave spy.[42]

Meade was severely criticized for not counterattacking Lee after the third day of battle. The next day Meade sent out skirmishers, but did not attack.[43] Lee had his army hold its position on Seminary Ridge all day on July 4th. The more than 10,000 wounded men would be moved by wagon train 40 miles (64 km) to Williamsport and cross the Potomac to Virginia. The rest of Lee's army followed on the night of July 4-5, screened by Jeb Stuart's cavalry.[43] The next day, on discovering the Confederates had left the battlefield, the Union army cautiously followed. At the Battle of Falling Waters, Lee's army was waiting for the floodedPotomac River to go down so his army could cross. Meade's forces caught up with them there but the battle had no clear victor. The Battle of Falling Waters was the last battle in the Gettysburg Campaign.[44]

After the battle, President Lincoln made a cemetery on the battlefield to honor the fallen soldiers.

↑By late 1862, Virginia was running out of food to feed its army.[11] Lee's horses were dying of disease because they had little or no fodder. The cavalry and artillery units had to be widely scattered behind his lines in order to find food for the horses.[11] In the winter of 1863, food trains from the south were becoming more and more scarce. One of Lee's main reasons for invading the North was to get supplies to continue the war. Lee's army foraged many of the small towns around Gettysburg for food and fodder.[12]

↑The addition of "shoes especially" in parentheses in Heth's report has blown up into one of the larger myths about Gettysburg.[19] It was even a question on the televisiongame showJeopardy!.[19] The misconception grew over many years, but was made larger by an 1897 newsletter of the American Podiatric Medical Association that stated there was a warehouse full of shoes at Gettysburg at the time.[18] There was no shoe factory or warehouse either in or near Gettysburg in 1863.[20] However there may have been a rumor at the time that shoes could be found there.[18] A few days earlier General Jubal Early's men came through Gettysburg and demanded a ransom including 1,500 pairs of shoes.[18] However, they left town empty handed.[18] All there was at Gettysburg in 1863 was a girl's school, a college and a carriage factory.[18] The battle at Gettysburg did not happen because of shoes.[19] It happened because 10 roads intersect at Gettysburg and both commanders had sent troops in that direction.[19]

↑Lee was used to giving discretionary, sometimes vague, orders leaving the final decision up to his commanders. He had done this routinely with General Stonewall Jackson, usually with great success.[22] But Jackson had been killed at Chancellorsville and Ewell had only recently been promoted to Corps commander. Ewell was used to following specific orders from Jackson that told him exactly what to do, not vague discretionary orders.[23] To add to the confusion, Lee repeated his earlier order not to cause a general engagement until the rest of the army had arrived.[24] Lee added he had no troops to support Ewell.[24]

↑Edwin B. Coddington, The Gettysburg Campaign; a study in command (New York: Scribner's, 1968), p. 573, See the discussion regarding historians' judgment on whether Gettysburg should be considered a decisive victory

↑John W. Busey; David G. Martin, Regimental Strengths and Losses at Gettysburg 4th ed. (Hightstown, NJ: Longstreet House, 2005), p. 260. See the section on casualties for a discussion of alternative Confederate casualty estimates, which have been cited as high as 28,000.